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Evrard B, Pizzi A, Mistakidis SI, Dag CB. Quantum Scars and Regular Eigenstates in a Chaotic Spinor Condensate. PHYSICAL REVIEW LETTERS 2024; 132:020401. [PMID: 38277581 DOI: 10.1103/physrevlett.132.020401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 11/28/2023] [Indexed: 01/28/2024]
Abstract
Quantum many-body scars consist of a few low-entropy eigenstates in an otherwise chaotic many-body spectrum, and can weakly break ergodicity resulting in robust oscillatory dynamics. The notion of quantum many-body scars follows the original single-particle scars introduced within the context of quantum billiards, where scarring manifests in the form of a quantum eigenstate concentrating around an underlying classical unstable periodic orbit. A direct connection between these notions remains an outstanding problem. Here, we study a many-body spinor condensate that, owing to its collective interactions, is amenable to the diagnostics of scars. We characterize the system's rich dynamics, spectrum, and phase space, consisting of both regular and chaotic states. The former are low in entropy, violate the eigenstate thermalization hypothesis, and can be traced back to integrable effective Hamiltonians, whereas most of the latter are scarred by the underlying semiclassical unstable periodic orbits, while satisfying the eigenstate thermalization hypothesis. We outline an experimental proposal to probe our theory in trapped spin-1 Bose-Einstein condensates.
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Affiliation(s)
- Bertrand Evrard
- Institute for Quantum Electronics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Andrea Pizzi
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Simeon I Mistakidis
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- ITAMP, Center for Astrophysics, Harvard and Smithsonian, Cambridge, Massachusetts 02138, USA
| | - Ceren B Dag
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- ITAMP, Center for Astrophysics, Harvard and Smithsonian, Cambridge, Massachusetts 02138, USA
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Chomaz L, Ferrier-Barbut I, Ferlaino F, Laburthe-Tolra B, Lev BL, Pfau T. Dipolar physics: a review of experiments with magnetic quantum gases. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2022; 86:026401. [PMID: 36583342 DOI: 10.1088/1361-6633/aca814] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Since the achievement of quantum degeneracy in gases of chromium atoms in 2004, the experimental investigation of ultracold gases made of highly magnetic atoms has blossomed. The field has yielded the observation of many unprecedented phenomena, in particular those in which long-range and anisotropic dipole-dipole interactions (DDIs) play a crucial role. In this review, we aim to present the aspects of the magnetic quantum-gas platform that make it unique for exploring ultracold and quantum physics as well as to give a thorough overview of experimental achievements. Highly magnetic atoms distinguish themselves by the fact that their electronic ground-state configuration possesses a large electronic total angular momentum. This results in a large magnetic moment and a rich electronic transition spectrum. Such transitions are useful for cooling, trapping, and manipulating these atoms. The complex atomic structure and large dipolar moments of these atoms also lead to a dense spectrum of resonances in their two-body scattering behaviour. These resonances can be used to control the interatomic interactions and, in particular, the relative importance of contact over dipolar interactions. These features provide exquisite control knobs for exploring the few- and many-body physics of dipolar quantum gases. The study of dipolar effects in magnetic quantum gases has covered various few-body phenomena that are based on elastic and inelastic anisotropic scattering. Various many-body effects have also been demonstrated. These affect both the shape, stability, dynamics, and excitations of fully polarised repulsive Bose or Fermi gases. Beyond the mean-field instability, strong dipolar interactions competing with slightly weaker contact interactions between magnetic bosons yield new quantum-stabilised states, among which are self-bound droplets, droplet assemblies, and supersolids. Dipolar interactions also deeply affect the physics of atomic gases with an internal degree of freedom as these interactions intrinsically couple spin and atomic motion. Finally, long-range dipolar interactions can stabilise strongly correlated excited states of 1D gases and also impact the physics of lattice-confined systems, both at the spin-polarised level (Hubbard models with off-site interactions) and at the spinful level (XYZ models). In the present manuscript, we aim to provide an extensive overview of the various related experimental achievements up to the present.
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Affiliation(s)
- Lauriane Chomaz
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
- Physikalisches Institut der Universität Heidelberg, Im Neuenheimer Feld 226, 69120 Heidelberg, Germany
| | - Igor Ferrier-Barbut
- Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
- Université Paris-Saclay, Institut d'Optique Graduate School, CNRS, Laboratoire Charles Fabry, 91127 Palaiseau, France
| | - Francesca Ferlaino
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - Bruno Laburthe-Tolra
- Université Sorbonne Paris Nord, Laboratoire de Physique des Lasers, F-93430 Villetaneuse, France
- CNRS, UMR 7538, LPL, F-93430 Villetaneuse, France
| | - Benjamin L Lev
- Departments of Physics and Applied Physics and Ginzton Laboratory, Stanford University, Stanford, CA 94305, United States of America
| | - Tilman Pfau
- Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
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Duan ZX, Wu WT, Lin YT, Yang SJ. Simple and active magnetic-field stabilization for cold atom experiments. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:123201. [PMID: 36586954 DOI: 10.1063/5.0119778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 11/08/2022] [Indexed: 06/17/2023]
Abstract
Cold atom experiments usually need a controllable and low-noise bias magnetic field to provide a quantization axis. Most labs need home-made stabilization of the field according to the actual setup, as commercially available power supply cannot directly satisfy their requirements. Here, by measuring the field fluctuations and active feedback modulating current supply of the applied magnetic field, we successfully demonstrate a field of 10.58 G with a stability to the level of 2.8 × 10-7 in a duration of 5 min. The root mean square noise is reduced to 0.05 mG, compared to the noise of 1.3 mG without stabilization. The coherence time of the magnetic-field sensitive transition between the rubidium ground states F=1,mF=-1 and 1,0, as measured by Rabi oscillation, is extended to 19.2 ms from the unstabilized value of 1.3 ms. This result is long enough for most experiments on quantum simulation and precision measurement. As our system has no passive magnetic shielding and additional compensation coils, it is highly simple and compact to provide the stable magnetic field and would be adapted to various applications with cold atoms.
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Affiliation(s)
- Zhi-Xin Duan
- Shenzhen Institute for Quantum Science and Engineering, School of Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Wei-Tao Wu
- Shenzhen Institute for Quantum Science and Engineering, School of Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yue-Tong Lin
- Shenzhen Institute for Quantum Science and Engineering, School of Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Sheng-Jun Yang
- Shenzhen Institute for Quantum Science and Engineering, School of Science, Southern University of Science and Technology, Shenzhen 518055, China
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Cominotti R, Berti A, Farolfi A, Zenesini A, Lamporesi G, Carusotto I, Recati A, Ferrari G. Observation of Massless and Massive Collective Excitations with Faraday Patterns in a Two-Component Superfluid. PHYSICAL REVIEW LETTERS 2022; 128:210401. [PMID: 35687467 DOI: 10.1103/physrevlett.128.210401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/28/2022] [Accepted: 04/19/2022] [Indexed: 06/15/2023]
Abstract
We report on the experimental measurement of the dispersion relation of the density and spin collective excitation modes in an elongated two-component superfluid of ultracold bosonic atoms. Our parametric spectroscopic technique is based on the external modulation of the transverse confinement frequency, leading to the formation of density and spin Faraday waves. We show that the application of a coherent coupling between the two components reduces the phase symmetry and gives a finite mass to the spin modes.
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Affiliation(s)
- R Cominotti
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - A Berti
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - A Farolfi
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - A Zenesini
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - G Lamporesi
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - I Carusotto
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - A Recati
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - G Ferrari
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
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Evrard B, Qu A, Dalibard J, Gerbier F. From Many-Body Oscillations to Thermalization in an Isolated Spinor Gas. PHYSICAL REVIEW LETTERS 2021; 126:063401. [PMID: 33635710 DOI: 10.1103/physrevlett.126.063401] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 01/13/2021] [Indexed: 06/12/2023]
Abstract
The dynamics of a many-body system can take many forms, from a purely reversible evolution to fast thermalization. Here we show experimentally and numerically that an assembly of spin-1 atoms all in the same spatial mode allows one to explore this wide variety of behaviors. When the system can be described by a Bogoliubov analysis, the relevant energy spectrum is linear and leads to undamped oscillations of many-body observables. Outside this regime, the nonlinearity of the spectrum leads to irreversibility, characterized by a universal behavior. When the integrability of the Hamiltonian is broken, a chaotic dynamics emerges and leads to thermalization, in agreement with the eigenstate thermalization hypothesis paradigm.
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Affiliation(s)
- Bertrand Evrard
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL Research University, Sorbonne Université, 11 Place Marcelin Berthelot, 75005 Paris, France
| | - An Qu
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL Research University, Sorbonne Université, 11 Place Marcelin Berthelot, 75005 Paris, France
| | - Jean Dalibard
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL Research University, Sorbonne Université, 11 Place Marcelin Berthelot, 75005 Paris, France
| | - Fabrice Gerbier
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL Research University, Sorbonne Université, 11 Place Marcelin Berthelot, 75005 Paris, France
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Farolfi A, Trypogeorgos D, Mordini C, Lamporesi G, Ferrari G. Observation of Magnetic Solitons in Two-Component Bose-Einstein Condensates. PHYSICAL REVIEW LETTERS 2020; 125:030401. [PMID: 32745386 DOI: 10.1103/physrevlett.125.030401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 02/11/2020] [Accepted: 06/11/2020] [Indexed: 06/11/2023]
Abstract
We experimentally investigate the dynamics of spin solitary waves (magnetic solitons) in a harmonically trapped, binary superfluid mixture. We measure the in situ density of each pseudospin component and their relative local phase via an interferometric technique we developed and as such, fully characterize the magnetic solitons while they undergo oscillatory motion in the trap. Magnetic solitons exhibit nondispersive, dissipationless longtime dynamics. By imprinting multiple magnetic solitons in our ultracold gas sample, we engineer binary collisions between solitons of either the same or opposite magnetization and map out their trajectories.
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Affiliation(s)
- A Farolfi
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - D Trypogeorgos
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - C Mordini
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - G Lamporesi
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - G Ferrari
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
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